This invention relates to a gun barrel of the type which can, for example, be used as a heavy, large-caliber gun barrel adapted to be mounted on tanks or the like (i.e. a tank cannon).
Many types of gun barrels form part of the state of the art. A primary object of the designers for all types of gun barrels is to achieve an increased target impact accuracy. To achieve this goal the gun barrels are (a) generally lengthened; (b) the length of the gun barrel along which it is supported is adjusted, or (c) other steps are taken which result in a reduction of the jump angle. There has been established as a standard, in particular for gun barrels mounted on tanks, a construction which includes a plural-stepwise-reduction of the gun barrel jacket diameter, which gun barrel is mounted in a support having a short supporting width. In order to increase the mass moment of inertia and to decrease the oscillations and vibrations of the barrel, the center of gravity of the recoiling mass was transferred from the support region of the gun barrel in the direction towards the muzzle of the gun barrel.
An arrangement for a gun barrel for reducing the jump angle of the projectile is described, for example, in German Pat. No. 19 11 067 (corresponding to U.S. Pat. No. 3,732,778). In this patent there is described an arrangement whereby there are mounted in the forward region of the gun barrel bending-oscillation-dampening stiffening members.
Such prior art gun barrels generally have a ratio of L/D&gt;52 (where L=axial length of the barrel and D=bore diameter). Such known gun barrels may have a stepwise reduction of the gun barrel jacket or a frusto-conical shape for the jacket whereby the exterior diameter of the gun barrel progressively diminishes in the direction toward the muzzle and may also have a constant internal bore diameter. Prior art gun barrels are generally supported along an exterior cylindrical rear portion of the gun barrel by means of front and rear cradles for absorbing the recoil and counter-recoil loads. Such known gun barrels are generally joined to additional recoiling massive parts at their rear portion. Such known gun barrels are, for example, described on page 316 of the HANDBOOK ON WEAPONRY by Rheinmetall published by Broenners Druckerei Breidenstein GmbH. Copyright 1982. The gun barrel of FIG. 833 has a stepped outer diameter jacket in its middle region and has a gun barrel support width of 7D. In the same publication there is shown in FIG. 927 a gun barrel in which the center of gravity is disposed between the front and rear cradles. There are also known gun barrels having a frustoconically shaped internal bore.
While the gun barrel described in U.S. Pat. No. 3,732,778 is designed to reduce the jump angle of a fired projectile, it can maintain essentially the same jump angle from one firing to the next. This drawback is due to changes in rigidity along the gun barrel which causes, in coaction with large support widths of &gt;7D, short whip lengths during firing. Also the center of gravity of the recoiling mass is disposed between the support cradles which results, at firing, in an indifferent support and leads to strong jump angle deviations causing unequal impulses from one firing to the next one.
It has been established that high-frequency bending oscillations of the gun barrel, which precede the projectile during its traverse through the barrel, negatively influence the target impact precision. The impact precision is primarily influenced by the jump angle, at which the projectile deviates from the target direction as it exits from the muzzle of the gun barrel.
In addition to the means described in U.S. Pat. No. 3,732,778 there exist a plurality of other parameters which influence the jump angle. Exemplary of such parameters are the constructional design data regarding the barrel, such as its mass distribution moment of inertia location inclusive of supplementary masses which are secured to the gun barrel, elastic rigidity of the barrel and the like, and constructional design data of the gun barrel support, for example width of the support, bearing clearance and the like, thereby disregarding other types of influences. It has been found to be particularly disadvantageous in gun barrels having a stepwise reduced gun barrel jacket diameter, having an exterior diameter reduction which progresses from the front support position of the barrel towards the muzzle, and in indifferently supported barrels, that uneven oscillation-causing pulses from firing to firing occur, which by themselves are already capable to cause purely incidental jump angles.